The effect of Kawasaki disease on childhood allergies - a sibling control study

Kawasaki disease and the environment: an enigmatic interplay

Kawasaki disease (KD) is a common systemic vasculitis of childhood. Although it has been almost 6 decades since Dr. Tomisaku Kawasaki reported the first case series of KD, the underlying cause remains a mystery. KD is a self-limiting disease. However, a dreaded complication is development of coronary artery abnormalities (CAAs). KD is the most common cause of acquired heart disease in children in the developed world and is being increasingly reported from developing countries too. Over the years, significant observations have been made about epidemiology of KD. It usually affects children below 5, has male preponderance and has significantly higher incidence in North East Asian countries. While several hypotheses have been proffered for etiology of KD, none have been conclusive. These include associations of KD epidemics in Japan and the United Stated with changes in tropospheric wind patterns suggesting wind-borne agents, global studies showing peaks of incidence related to season, and increased rates in populations with a higher socioeconomic profile related to hygiene hypothesis and vaccination. Furthermore, the self-limiting, febrile nature of KD suggests an infectious etiology, more so with sudden decline noted in cases in Japan with onset of COVID-19 mitigation measures. Finally, single nucleotide polymorphisms have been identified as possible risk alleles in patients with KD and their significance in the pathogenesis of this disease are also being defined. The purpose of this review is to elucidate the puzzling associations of KD with different environmental factors. Looking at patterns associated with KD may help us better predict and understand this disease.

Comparison of Previous Infectious and Allergic Diseases Between Patients with Kawasaki Disease and Propensity Score-matched Controls: A Nationwide Cohort Study

OBJECTIVE

To determine whether previous infectious and allergic diseases are associated with the development of Kawasaki disease in children.

STUDY DESIGN

This nationwide, population-based, case-control study used data from the Korean National Health Insurance claims database. The entire cohort consisted of patients younger than 5 years of age diagnosed with Kawasaki disease and 1:5 propensity score-matched controls from 2013 to 2019. The epidemiologic features and previous infectious or allergic diseases between the 2 groups were compared, and potential factors that could influence the association were identified.

RESULTS

In total, 32 964 patients diagnosed with Kawasaki disease and 164 820 controls were included. Patients with Kawasaki disease had more frequent diagnoses of previous sepsis or bacteremia (OR 1.41), acute pyelonephritis (OR 1.10), and otitis media (OR 1.24). In addition, Kawasaki disease was associated with previous diagnoses of atopic dermatitis (OR 1.05), urticaria (OR 1.08), and asthma (OR 1.05). The association between previous infectious or allergic diagnoses and Kawasaki disease was more prominent in younger patients (<2 years). However, intravenous immunoglobulin resistance, sex, and region of residence were not significant factors that consistently influenced the association between previous infectious or allergic diseases and Kawasaki disease.

CONCLUSIONS

Despite the increased rates of previous infectious and allergic diseases in patients with Kawasaki disease compared with controls, the association between allergic diseases and Kawasaki disease was weaker in our cohort than in previous studies.

Atopic asthma as a potentially significant but unrecognized risk factor for Kawasaki disease in children

OBJECTIVES

Childhood asthma is known to be associated with risks of both respiratory and non-respiratory infections. Little is known about the relationship between asthma and the risk of Kawasaki disease (KD). We assessed associations of asthma status and asthma phenotype (e.g. atopic asthma) with KD.

METHODS

We performed a population-based retrospective case-control study, using KD cases between January 1, 1979, and December 31, 2016, and two matched controls per case. KD cases were defined by the American Heart Association diagnostic criteria. Asthma status prior to KD (or control) index dates was ascertained by the two asthma criteria, Predetermined Asthma Criteria (PAC) and Asthma Predictive Index (API, a surrogate phenotype of atopic asthma). We assessed whether 4 phenotypes (both PAC + and API+; PAC + only; API + only, and non-asthmatics) were associated with KD.

RESULTS

There were 124 KD cases during the study period. The group having both PAC + and API + was significantly associated with the increased odds of KD, compared to non-asthmatics (odds ratio [OR] 4.3; 95% CI: 1.3 - 14.3). While asthma defined by PAC was not associated with KD, asthma defined by PAC positive with eosinophilia (≥4%) was significantly associated with the increased odds of KD (OR: 6.7; 95% CI: 1.6 - 28.6) compared to non-asthmatics. Asthma status defined by API was associated with KD (OR = 4.7; 95% CI: 1.4-15.1).

CONCLUSIONS

Atopic asthma may be associated with increased odds of KD. Further prospective studies are needed to determine biological mechanisms underlying the association between atopic asthma and increased odds of KD.

The Long-term Cardiac and Noncardiac Prognosis of Kawasaki Disease: A Systematic Review

CONTEXT

It is uncertain if children with Kawasaki Disease (KD) are at risk for non-cardiac diseases and if children with KD but without coronary artery aneurysms (CAA) are at risk for long-term cardiac complications.

OBJECTIVE

To determine the long-term mortality and prognosis of children after KD.

DATA SOURCES

Medline, Embase, and the Cochrane Central Register.

STUDY SELECTION

Controlled trials and observational studies were included if they included children with KD and reported mortality, major adverse cardiovascular events (MACE), chronic cardiac or other disease over an average follow-up of ≥1 year.

DATA EXTRACTION

Data extracted included sample size, age at diagnosis, the proportion with coronary artery aneurysms (CAA), follow-up duration, and outcome(s).

RESULTS

Seventy-four studies were included. Thirty-six studies reported mortality, 55 reported a cardiac outcome, and 12 reported a noncardiac outcome. Survival ranged from 92% to 99% at 10 years, 85% to 99% at 20 years, and 88% to 94% at 30 years. MACE-free survival, mostly studied in those with CAA, varied from 66% to 91% at 10 years, 29% to 74% at 20 years, and 36% to 96% at 30 years. Seven of 10 studies reported an increased risk in early atherosclerosis. All 6 included studies demonstrated an increased risk in allergic diseases.

LIMITATIONS

Our study may have missed associated chronic comorbidities because short-term studies were excluded. The majority of outcomes were evaluated in East-Asian patients, which may limit generalizability. Studies frequently excluded patients without CAA and did not compare outcomes to a comparison group.

CONCLUSIONS

Studies demonstrate >90% survival up to 30 years follow-up. MACE is observed in children with CAA, but is not well studied in those without CAA.

High Serum Total IgE at Admission Is Associated with Coronary Artery Lesions in Children with Kawasaki Disease

Kawasaki disease (KD) is associated with allergy. As immunoglobulin E (IgE), a key element of allergic reactions, is related with coronary heart disease, we evaluated the serum total IgE levels, and investigated its clinical relevance in 339 children with KD. These patients were classified as high IgE group and normal IgE group according to the reference value of IgE. Serum IgE levels in the high group (279.76 ± 202.54 IU/mL) significantly increased compared with the normal group (5.51 ± 15.79 IU/mL) (p < 0.001). There were also no significant differences in the frequency of major clinical manifestation between the two groups. The number of patients who developed coronary artery lesions (CALs) was significantly higher in the high group (p = 0.004), and the serum levels of IgE were also markedly higher in the KD patients with CALs than in patients without CALs (p = 0.002). High total serum IgE was an independent prognostic for CALs in the multivariate analysis. In conclusion, serum IgE levels may be associated with CALs in children with KD.

Increased Risk of Asthma and Allergic Rhinitis in Patients With a Past History of Kawasaki Disease: A Systematic Review and Meta-Analyses

Background: Allergic diseases are frequently observed in children with Kawasaki disease (KD). However, the evidence supporting the association between KD and allergies has been conflicting. The objective of the current study is to examine the association between KD and allergic diseases. Methods: We conducted an electronic search using PubMed, Embase, and the Cochrane through 24 July 2021. The inclusion criteria consisted of studies that examined the prevalence of allergic diseases in children with a previous diagnosis of KD and in a comparison group. We pooled studies by using a random effects model. The effects of KD on the subsequent risk of allergic diseases were expressed as odds ratio (OR) with 95% confidence intervals (CI). Results: We included a total of four studies that assessed the effect of KD on asthma, allergic rhinitis, and atopic dermatitis vs. non-KD children (KD individuals for asthma, four studies, n = 8,474; allergic rhinitis, four studies, n = 8,474; atopic dermatitis, three studies, n = 8,330). The overall prevalence of asthma, allergic rhinitis, and atopic dermatitis was 9.12, 27.63, and 6.55% among patients with previous KD. The meta-analysis showed a significantly increased risk of asthma (OR:1.437, CI: 1.067-1.937) and allergic rhinitis (OR: 1.726, CI: 1.291-2.307) in patients with KD, compared with the control groups. However, patients with KD did not have a significantly different level of risk of atopic dermatitis (OR: 1.243, 95% CI: 0.857-1.802). Conclusion: This meta-analysis supports that individuals with KD are more likely to have asthma and allergic rhinitis compared to controls.

Hygiene Hypothesis as the Etiology of Kawasaki Disease: Dysregulation of Early B Cell Development

Kawasaki disease (KD) is an acute systemic vasculitis that occurs predominantly in children under 5 years of age. Despite much study, the etiology of KD remains unknown. However, epidemiological and immunological data support the hygiene hypothesis as a possible etiology. It is thought that more sterile or clean modern living environments due to increased use of sanitizing agents, antibiotics, and formula feeding result in a lack of immunological challenges, leading to defective or dysregulated B cell development, accompanied by low IgG and high IgE levels. A lack of B cell immunity may increase sensitivity to unknown environmental triggers that are nonpathogenic in healthy individuals. Genetic studies of KD show that all of the KD susceptibility genes identified by genome-wide association studies are involved in B cell development and function, particularly in early B cell development (from the pro-B to pre-B cell stage). The fact that intravenous immunoglobulin is an effective therapy for KD supports this hypothesis. In this review, I discuss clinical, epidemiological, immunological, and genetic studies showing that the etiopathogenesis of KD in infants and toddlers can be explained by the hygiene hypothesis, and particularly by defects or dysregulation during early B cell development.

Is there any association between asthma and Kawasaki disease? A systematic review and meta-analysis

OBJECTIVE

Shared immune factors are involved in the pathogenesis of asthma and Kawasaki disease (KD). Consequently, several observational studies have explored an association between KD and asthma. This systematic review and meta-analysis aimed to explore the association between KD and asthma.

METHODS

PubMed and Embase databases were searched for cross-sectional, case-control and cohort studies that investigated the association between KD and asthma. The first author, publication year, study type, sample size, and participant demographics were retrieved. The association between KD and asthma was expressed by the odds ratio (OR) and 95% confidence interval (CI).

RESULTS

Eleven studies were eligible in the systematic review. The crude ORs (cORs) were extracted from 11 studies, and seven of them also provided adjusted ORs (aORs). The cORs between KD and asthma was 1.53 (95% CI, 1.29-1.81). After adjustment for some confounding factors (age, sex, region), asthma also had an association with KD (aOR, 1.08; 95% CI, 1.00-1.17). The subgroup analyses showed the study design and study location to influence between-study heterogeneity. Analyses of aOR values revealed that asthma onset before KD onset does not appear to increase KD prevalence, whereas people suffering from KD could increase the prevalence of developing asthma.

CONCLUSION

Our meta-analysis suggested a possible association between preceding KD and asthma onset, but care must be taken when interpreting this result. Prospective cohort studies are needed to assess a causal relationship between these two diseases.

IgA Levels Are Associated with Coronary Artery Lesions in Kawasaki Disease

Background and Objectives

Kawasaki disease (KD) is an acute systemic vasculitis that affects the coronary arteries. Abnormal immune reactions are thought to contribute to disease pathogenesis. The effect of immunoglobulin (Ig) isotype (IgG, IgA, IgM, and IgE) on inflammatory data and clinical outcomes of patients with KD was examined.

Methods

Ig levels in 241 patients with KD were measured during the acute, subacute, convalescent, and normal phases of the disease.

Results

Compared with reference Ig values, IgG, IgA, and IgM levels were significantly higher in the subacute phase, while IgE levels were elevated in 73.9% (178/241) of patients with KD in all clinical phases. However, high IgE levels were not associated with clinical outcomes, including intravenous immunoglobulin unresponsiveness and coronary artery lesions (CALs). Significantly more CALs were observed in the high IgA group than in the normal IgA group (44.7% vs. 20.8%, respectively; p<0.01). In addition, IgA levels in the acute phase (p=0.038) were 2.2-fold higher, and those in the subacute phase were 1.7-fold higher (p <0.001), in the CAL group than in the non-CAL group. IgA concentrations increased along with the size of the coronary artery aneurysm (p <0.001). Furthermore, there was a strong correlation between IgA levels and CAL size (r=0.435, p<0.001), with a high odds ratio of 2.58 (p=0.022).

Conclusions

High IgA levels in patients with KD are prognostic for the risk of CALs.

Kawasaki Disease and Allergic Diseases

Background: Kawasaki disease (KD) is an inflammatory disorder with an unknown etiology. It is the leading cause of acquired heart disease, which leads to coronary vasculitis among children. Studies of frequent manifestation of allergic diseases in children with KD have been the subject of mounting clinical interest. However, evidence supporting the association between KD and allergies has yet to be systematically reviewed. Methods: In this article, we reviewed current literature regarding the association between KD and allergic diseases. References for this review were identified through searches of PubMed, Cochrane, and Embase through the end of August 2020. Results: The results of the analyses of immune repertoire, clinical, and epidemiological studies have indicated some of the characteristics of infectious disease for KD. Although some allergic disorders, such as asthma, may be exacerbated by viral infections, allergies are typically caused by an allergen that triggers an immune response, with the potential involvement of type 2 inflammation and immune disturbances leading to tissue remodeling in genetically susceptible hosts. The effect of intravenous immunoglobulin is multi-faceted and results in a decrease in activating Fc gamma receptor IIA and an increase in anti-inflammatory eosinophils. The findings from this review demonstrate that children who have suffered from KD are more likely to have allergic rhinitis than the general population and their siblings, a condition that lasts until the age of 17. When followed up as teenagers and adults, children with KD are more likely to develop urticaria. Conclusions: This review supports that allergic diseases, such as allergic rhinitis, have been demonstrated to increase following KD. Therefore, the importance of allergic diseases in patients with KD should be emphasized in long-term care. Interventions that include strategies for managing allergies in children with KD would be beneficial.

Lower CMV and EBV Exposure in Children With Kawasaki Disease Suggests an Under-Challenged Immune System

Background: Kawasaki Disease (KD) is a pediatric vasculitis of which the pathogenesis is unclear. The hypothesis is that genetically pre-disposed children develop KD when they encounter a pathogen which remains most often unidentified or pathogen derived factors. Since age is a dominant factor, prior immune status in children could influence their reactivity and hence the acquisition of KD. We hypothesized that systemic immune responses early in life could protect against developing KD. With this study we tested whether the incidence of previous systemic cytomegalovirus (CMV) or Epstein-Barr virus (EBV) infection is lower in children with KD compared to healthy age-matched controls. Methods and Results: We compared 86 KD patients with an age-matched control group regarding CMV and EBV VCA IgG measurements (taken before or 9 months after IVIG treatment). We found that both CMV and EBV had an almost 2-fold lower seroprevalence in the KD population than in the control group. Conclusions: We suggest that an under-challenged immune system causes an altered immune reactivity which may affect the response to a pathological trigger causing KD in susceptible children.

Enterovirus Infection and Subsequent Risk of Kawasaki Disease: A Population-based Cohort Study

BACKGROUND

The relationship of enterovirus (EV) infection and Kawasaki disease (KD) is still unclear. The purpose of this study was to conduct a population-based cohort study to determine the relationship between KD and EV infection in Taiwan.

METHODS

A population-based cohort study was conducted to analyze the children file (age < 18 years) of the Taiwan National Health Insurance program between 2000 and 2008. In total, 285,636 children with EV infection and 285,636 children without EV infection were included and followed up. The subsequent KD was the major outcome event.

RESULTS

The cumulative incidence of KD was significantly higher in the EV-infected cohort than in the non-EV-infected cohort (log-rank test, P < 0.001). The overall incidence of KD was 56% higher in the EV-infected cohort than in the non-EV-infected cohort, with an adjusted hazard ratio of 1.56 (95% confidence interval: 1.44-1.69). Stratified analysis showed higher KD risk associated with previous EV infection in children 3-5 years old, in girls, in children living in less urbanization levels, in children with parental low-income occupation, and in children with allergic diseases.

CONCLUSIONS

There is a higher association between KD and previous EV infection in Taiwanese children, especially in those 3-5 years old, with female sex, with less urbanization level, with low-income parental occupation, and with allergy.

Atopic Predilection among Kawasaki Disease Patients: A Cross-Sectional Study of 1,187,757 Teenagers

BACKGROUND

Kawasaki disease (KD) is an acute, systemic vasculitis in children, with an etiology that is not completely understood. It is assumed that the development of KD is mediated by an immunologic response. Several reports from East Asia have found a higher prevalence of atopic diseases among patients with KD, but a large-scale study of a non-Asian population regarding this correlation is still lacking. The purpose of this article was to achieve this goal.

METHODS

We conducted a cross-sectional, large-scale study to estimate the correlation of KD with allergic diseases. The medical history of 1,187,757 Israeli teenagers (aged 16-20 years during the years 1998-2013) was retrieved. The study population was divided into 3 groups according to a past history of noncomplicated and complicated KD and a control group. The prevalence of allergic diseases among these groups was further investigated.

RESULTS

The prevalence of atopic diseases in the 3 study groups was presented (asthma in 11.4, 8.1 and 3.5%, respectively; angioedema/urticaria in 7.1, 0 and 0.46%, respectively; allergic rhinitis in 20, 12.1 and 6.7%, respectively). In noncomplicated KD, a statistically significant link to asthma [odds ratio (OR) 2.4; p = 0.048] and a borderline significant link to allergic rhinitis (OR 1.9; p = 0.06) were found. In KD complicated with cardiac disease, statistically significant links were found for all the allergic conditions, asthma (OR 3.5; p = 0.003), allergic rhinitis (OR 3.5; p < 0.001) and angioedema/urticaria (OR 16.48; p < 0.001).

CONCLUSION

KD is associated with allergic diseases. This association increases with the severity of the disease.

T-Helper Cytokine Profiles in Patients with Kawasaki Disease

Background and Objectives

Kawasaki disease is an acute systemic vasculitis of which pathogenesis suspected is caused by immune dysregulation. The goal of this study is to evaluate the activation pattern of T helper cell type 1 (Th1) and T helper cell type 2 (Th2) in patients with Kawasaki disease.

Subjects and Methods

Prospective study of 60 patients (male 36, female 24) with diagnosis of Kawasaki disease were enrolled. One hundred and eighty blood samples from these patients were collected according to the different clinical stages {before initial intravenous immunoglobulin (IVIG), 5 days after initial IVIG, 2 months after initial IVIG}. The plasma level of Th1 cytokines; interferon-gamma (IFN-γ) & interleukin (IL)-2 and Th2 cytokines; IL-4 & IL-10 were measured by enzyme-liked immunosorbent assay.

Results

In all patients, the plasma level of Th1 cytokines (IFN-γ, IL-2) and Th2 cytokines (IL-4 and IL-10) were markedly elevated during the acute stage of Kawasaki disease. Since then, the plasma level of all these cytokines decreased significantly along with the process of clinical stages. Regardless of the existence of coronary artery lesion or no response to initial IVIG treatment, there were no significant differences between them.

Conclusion

These data suggest that both Th1 and Th2 cells may be activated simultaneously during the acute stage of Kawasaki disease. Further studies are therefore required to establish the difference of activation pattern of T helper cells between Kawasaki disease and other inflammatory diseases.

IL-31 associated with coronary artery lesion formation in Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is known to be associated with T help (Th) 2 reaction and subsequently allergic diseases. Interleukin-31 (IL-31) has also been reported to be involved in Th2 mediated diseases such as allergic diseases. However, the role of IL-31 in KD has not been previously reported. The aim of this study is to investigate whether IL-31 is associated with KD and its clinical outcome.

MATERIAL

A total of 78 KD patients who met the criteria of KD were enrolled in this study as well as 20 age-matched controls. Plasma samples were conducted to measure IL-31 before intravenous immunoglobulin (IVIG) treatment (KD1), within 3 days after IVIG treatment (KD2) and at least 3 weeks after IVIG treatment (KD3) by utilizing enzyme-linked immunosorbent assay (ELISA).

RESULT

Our findings showed that IL-31 expression was higher in KD patients after IVIG treatment significantly (KD2>KD1: 1265.0±199.3 vs. 840.2±152.5 pg/ml, p<0.0001). Further analysis revealed that IL-31 level was significantly higher in KD patients with coronary artery lesion (CAL) (656.6±139.5 vs. 1373.0±422.0 pg/ml, p = 0.04) before IVIG treatment (KD1). There were no significant differences between the IVIG resistance and IVIG responsiveness groups.

CONCLUSION

IL-31 was increased after IVIG treatment in patients with KD and was significantly associated with CAL formation. The results from this study may help to identify a novel risk factor for predicting KD and CAL formation.

Increased risk of Kawasaki disease in children with common allergic diseases

PURPOSE

Growing evidence reveals a link between Kawasaki disease (KD) and allergic diseases. This population-based case-control study is to investigate the onset of allergic diseases in children and the associated risks of KD.

METHODS

From 1996 to 2008, 2748 children with KD and 10,656 randomly selected controls were enrolled. Odds ratios of KD were calculated for the association with pre-existing allergic diseases.

RESULTS

The children with a single allergic disease had an increased risk of KD, with adjusted odds ratios of having KD of 1.82 for urticaria (95% confidence interval [CI], 1.54-2.14), 1.44 for allergic rhinitis (95% CI, 1.23-1.70), and 1.22 for atopic dermatitis (95% CI, 1.06-1.39). The adjusted odds ratios increased with the number of concurrent allergic diseases, from 1.61 (95% CI, 1.43-1.82) for those with only one allergic disease to 1.71 (95% CI, 1.48-1.98) for those with at least two allergic diseases. The children who made two or more medical visits for associated allergic diseases per year had an increased risk of KD.

CONCLUSIONS

Children with onset of allergic diseases were at increased risk for KD, and the increased risk was associated with the cumulative effect of concurrent allergic diseases and frequency of seeking medical care.

Atopic diathesis in patients with Kawasaki disease

OBJECTIVE

To determine the association between Kawasaki disease (KD) and atopic diathesis (atopic dermatitis [AD], allergic rhinitis, and asthma) in children younger than 5 years of age.

STUDY DESIGN

In this nationwide study, we aimed to analyze the association and temporal relationship between KD and atopic diathesis. Data were obtained from the National Health Insurance Research Database of Taiwan from 1997 to 2010. In total, 200 patients with KD younger than 5 years of age and 800 age- and sex-matched control subjects were enrolled.

RESULTS

In the whole study population, an increased risk of any concomitant atopic diseases was observed in patients with KD (OR 1.61, 95% CI 1.15-2.26). The risk of AD was increased in male patients between 1 and 5 years of age (OR 3.02, 95% CI 1.22-7.50). More than 60% of the patients developed atopic diseases after the diagnosis of KD.

CONCLUSION

There appears to be an association between KD and risk of AD. Most of the atopic diseases occurred after the episode of KD.

Increased risk of atopic dermatitis in preschool children with kawasaki disease: a population-based study in taiwan

Kawasaki disease (KD) is an acute febrile systemic vasculitis and has been reported to be associated with allergic disease. The risk of atopic dermatitis (AD) in preschool children with KD has not been investigated. The study was to determine the longitudinal risk of the development of AD in preschool children with KD. A nationwide 5-year population-based study was performed using data from the National Health Insurance Database in Taiwan between 1999 and 2003. The risk factors for AD were compared between the 2 study groups during the follow-up period using the Cox proportional hazards model. In addition, plasma interleukin (IL)-5 levels were analyzed in normal subjects and KD patients. Among the 1440 subjects included, 21.6% developed AD during the 5-year follow-up period, of which 30.3% and 18.7% belonged to the study cohort and the comparison group, respectively. Children with KD were 1.25 times more likely to have AD than those in controls (P = 0.04). Levels of IL-5 and IgE were significantly higher in KD patients. Children with KD had a higher risk of developing AD during the 5-year follow-up period than the control group. Increased IL-5 and IgE levels may be key factors contributing to the risk of AD.

Kawasaki disease and subsequent risk of allergic diseases: a population-based matched cohort study

Background

The risk of allergic diseases among Kawasaki disease (KD) patients relative to the general population is not known. The aim of this study was to perform a population-based cohort study to investigate the risk of allergic diseases among children after KD in Taiwan- a country with the third highest incidence of KD in the world.

Methods

Data were obtained from the Taiwan National Health Insurance Research Database. In total, 253 patients who were 5 years of age or younger and had a first-time hospitalization with a diagnosis of KD between 1997 and 2005 were included as the study cohort and 1,012 non-KD patients matched for age and sex were included as comparison cohort. Multivariate Cox proportional hazard regression model was used to adjust for confounding and to compare the 6-year allergic-free survival rate between these two cohorts.

Results

The incidence rate of allergic diseases (184.66 per 1000 person-year) was significantly higher in the KD cohort than in the control cohort (124.99 per 1000 person-years). After adjusting for potential confounders, the adjusted hazard ratios of asthma and allergic rhinitis were 1.51 (95% confidence interval = 1.17-1.95) and 1.30 (95% confidence interval = 1.04-1.62), respectively.

Conclusion

We conclude that KD patients were at an increased risk for allergic diseases compared with the comparison cohort.

Echocardiographic alterations in a child with cow's milk allergy: a case report

Introduction

Cow’s milk allergy is the most frequent food allergy in Europe and western countries and shows a wide spectrum of clinical features, including atopic dermatitis and gastrointestinal disease. To the best of our knowledge, this report is the first to describe Kawasaki disease-like clinical features and echocardiographic alterations which resolved after a cow’s milk-free diet.

Case presentation

We report a case of a 9-month-old Caucasian girl with atopic dermatitis who developed clinical features commonly present in Kawasaki disease (erythematous skin rash, non-exudative conjunctivitis, fissured lips and neck lymph nodes), together with mild echocardiographic alterations (perivascular brightness, pericardial effusion) in the absence of fever. These features resolved within 2 weeks after the beginning of a cow’s milk-free diet.

Conclusion

Kawasaki disease has recently been considered a possible risk factor for subsequent allergic disease secondary to immune dysfunction. This case report suggests that the immune-related alterations which are commonly present in allergic patients could be similar to the antigen-related immune response in Kawasaki disease and thus could lead to similar clinical features.

Comparison of the laboratory data between Kawasaki disease and enterovirus after intravenous immunoglobulin treatment

Kawasaki disease (KD) is a systemic vasculitis of unknown etiology. The laboratory findings before and after intravenous immunoglobulin (IVIG) in KD have been discussed, but the characteristics of IVIG therapy still are unclear. This study aimed to compare laboratory data from patients with KD and enterovirus (EV) infection to evaluate the differences after IVIG therapy. The study enrolled 171 KD patients and 38 EV patients treated with a single dose of IVIG from 2003 to 2010. Laboratory data including total white blood cell counts (WBC) and hemoglobin (Hb), platelet, segment, lymphocyte, eosinophil, and monocyte levels were analyzed. Compared with the KD patients, the EV patients had higher Hb, lymphocyte, and monocyte levels and lower eosinophil levels before IVIG treatment (p < 0.05). After IVIG treatment, the KD patients had lower Hb and segment levels but higher platelet, lymphocyte, and eosinophil levels than the EV patients (p < 0.05). In the KD patients, the platelet, eosinophil, and monocyte levels increased after IVIG treatment, whereas Hb, WBC, and segment levels decreased significantly (p < 0.001). In the EV patients, eosinophil levels increased after IVIG treatment, whereas WBC and Hb levels decreased significantly (p < 0.05). The study results provide evidence that eosinophilia may be related to IVIG therapy in KD and EV patients. The KD patients had higher eosinophil levels both before and after IVIG therapy than the EV patients, which may have been due to the inflammatory mechanism of KD. The KD patients had higher platelet levels than the EV patients, suggesting that platelets are involved in the inflammatory response to KD.

Hospitalisation with infection, asthma and allergy in Kawasaki disease patients and their families: genealogical analysis using linked population data

BACKGROUND

Kawasaki disease results from an abnormal immunological response to one or more infectious triggers. We hypothesised that heritable differences in immune responses in Kawasaki disease-affected children and their families would result in different epidemiological patterns of other immune-related conditions. We investigated whether hospitalisation for infection and asthma/allergy were different in Kawasaki disease-affected children and their relatives.

METHODS/MAJOR FINDINGS

We used Western Australian population-linked health data from live births (1970-2006) to compare patterns of hospital admissions in Kawasaki disease cases, age- and sex-matched controls, and their relatives. There were 295 Kawasaki disease cases and 598 age- and sex-matched controls, with 1,636 and 3,780 relatives, respectively. Compared to controls, cases were more likely to have been admitted at least once with an infection (cases, 150 admissions (50.8%) vs controls, 210 admissions (35.1%); odds ratio (OR) = 1.9, 95% confidence interval (CI) 1.4-2.6, P = 7.2×10⁻⁶), and with asthma/allergy (cases, 49 admissions (16.6%) vs controls, 42 admissions (7.0%); OR = 2.6, 95% CI 1.7-4.2, P = 1.3×10⁻⁵). Cases also had more admissions per person with infection (cases, median 2 admissions, 95% CI 1-5, vs controls, median 1 admission, 95% CI 1-4, P = 1.09×10⁻⁵). The risk of admission with infection was higher in the first degree relatives of Kawasaki disease cases compared to those of controls, but the differences were not significant.

CONCLUSION

Differences in the immune phenotype of children who develop Kawasaki disease may influence the severity of other immune-related conditions, with some similar patterns observed in relatives. These data suggest the influence of shared heritable factors in these families.